1. Field of the Invention
The present invention relates to a solar cell module, a method of producing it, and a solar cell array, a building material, a solar-cell-integrated roof, or a power generation apparatus having a plurality of such solar cell modules connected to each other, and a construction method and a maintenance and inspection method thereof.
2. Related Background Art
When using solar cell modules, durability with respect to the external environment, including temperature, humidity, and impact, is required. Therefore, ordinary solar cell modules are constructed such that: solar cells are sealed with a filler; a weather-resistant film or glass is provided as a protective material on the top surface side thereof; and a reinforcing member or outer member is mounted on the periphery and bottom surface thereof. Most of such members are made of a metal.
From the viewpoint of electrical safety, measures are taken to electrically ground the outer conductor members of solar cell modules. In this way, even if one touches the outer conductor member of a solar cell module, the person does not receive an electrical shock.
FIGS. 1A and 1B are views for explaining an example of a solar cell array using solar cell modules, which are a schematic perspective view and a schematic sectional view thereof, respectively.
In the solar cell array illustrated in FIGS. 1A and 1B, frames 107 of solar cell modules 101 are mounted on mounting members 111 of a stand 102 by fixing means 108 such as bolts. The solar cell devices are attached to the frames 107 with a buffer material 112 being interposed between them. Each of the solar cell modules held by the frames 107 is constructed, for example, in a process wherein a solar cell 103 is sealed with a resin 104 on a glass sheet 105 and a back surface film 106 covers the sealed member, as illustrated in the figure.
In the solar cell array for the photovoltaic power generation apparatus of the stand mounting type as illustrated in FIGS. 1A and 1B, grounding of the apparatus is effected by leading a single-core insulated wire 109 out from a junction 110 at a part of the metal frame 107 or stand 102.
FIG. 2 is a schematic sectional view showing an example of the solar cell array for a photovoltaic power generation apparatus which also functions as a roofing material (simply referred to as roofing material-integrated type photovoltaic power generation apparatus). In FIG. 2, reference numeral 201 designates solar cell modules having solar cells, 202 a clip, 203 screws, 204 a cover, 205 a metal rafter, 206 a tapping screw, 207 a bolt, and 208 a base material.
Further, in the solar cell array for the photovoltaic power generation apparatus of the roofing material-integrated type as illustrated in FIG. 2, it is conceivable to take measures to electrically connect outer conductor portions 210 of the solar cell modules 201 through the clip 202 and screws 203 to the metal rafter 205 and to further ground the metal rafter.
However, the grounding method in the stand mounting type solar cell apparatus as described above was problematic in that the solar cell modules had to be mounted on the stand securely with electrical connection and a grounding conductor had to be prepared separately from distribution lines or the grounded portion of the solar cell modules were exposed and beaten by the weather thereby causing an increase in resistance. Further, in the case of the grounding method in the roofing material-integrated type solar cell apparatus as described above, in addition to the above problems, it was necessary to prepare members different from the normally used roofing parts or specially processed members for grounding, thereby causing lowered operability in construction of the roofing-material-integrated solar cells. Further, in some cases there also arose a problem that it was difficult to carry out measurement in maintenance or inspection of the grounded portion.